(1) Field of the Invention
The present invention relates to a seat belt retractor with an emergency locking mechanism. The retractor is for use with an automotive or other vehicle. More particularly the present invention relates to a seat belt retractor having two seat belt retracting shafts with ratchet wheels and a single emergency locking mechanism whereby both seat belt retracting shafts can be locked simultaneously in case of emergency.
(2) Statement of the Prior Art
In a conventional seat belt retractor with an emergency locking mechanism, a seat belt is normally wound on a retracting shaft, biased in the retract direction on the shaft by means of a return spring attached to the shaft.
With conventional retractors when an automotive vehicle collides with an object, an inertia sensor in the form of a weight swings and a flat head supporting the weight tilts due to the vehicle's inertia force. The inclination of the flat head causes an angular movement of an actuating means to push against a lock pawl. Consequently, the lock pawl, provided beside a ratchet wheel attached to the retracting shaft, engages the rotating ratchet wheel, thus locking the movement of the retracting shaft.
However, in the construction of such conventional seat belt retractors, two seat belt retractors for two seat belts need to be provided when each seat belt is spooled out separately from a space between two parallel seats. Therefore, two inertia sensors are required for locking the rotational movements of the seat belt retracting shafts. Consequently, the construction of such conventional seat belt retractors requires more space and is uneconomical.